The only safe way is Carnauba wax.
Fine sand(1000) the rim down to un-darkened wood. Shape it as it originally was or as you please.
3000 grit to finish.
Fast buffer with Carnauba.
Recently picked this one up in Arkansas.
Hoping y'all can shed some light on who the maker is.
The stem is not original.
Looks to me the markings are -- S M 10 87
Many Thanks